The present invention relates to new and useful improvements in fluid pumps and more particularly to centrifugal pumps.
Centripetal pumps are well known and generally include a rotatable outer rotor housing and a stator comprising a stationary inner pitot tube within the rotatable housing. Fluid is pumped into the rotating housing and the velocity of the fluid is increased and the centrifugal forces induced by the rotating housing directs the fluid to the extremities thereof to be discharged through the pitot tube.
Typical of these prior art devices are such as that disclosed in such patents as U.S. Pat. No. 3,180,268 to Willus and U.S. Pat. No. 3,936,214 to Zupanick. In the Willus patent there is disclosed a high speed dynamic fluid pump consisting of an outer rotary housing which rotates around an inner stationary pitot. The fluid pump pulls the fluid into the pump chamber and then exhausts the fluid outwardly in the same direction and includes means for bleeding air from the pumpable fluid. The Zupanick patent on the other hand discloses a two-phase rotary pump consisting of an outer rotary member and a stationary inner pitot. The pump of this patent pulls two-phase fluids into a pump chamber through a suitable conduit and centrifugal forces are developed by rotary member. A dense fluid is pumped out of the pump chamber through one orifice and a lighter phase fluid is pumped through a second orifice.
Although these known type pumps utilizing rotary pump impellers exteriorally arranged to a stator element may be acceptable for use in certain applications they have not been proven readily adaptable for use in handling fluids having a high foam or air content which is fed to the pump in relatively high volumes. Typical of such fluids are filtrates developed in paper and pulp mill processes in brownstock washing and deckering steps.
It is an object of the present invention to provide a novel centrifugal pump.
Another object is to provide a centrifugal pump having novel means for breaking high volumes of foam and deaerating liquid feed streams and further capable of pumping intermittent flows.
It is still a further object to provide a novel compact, high volume positive displacement centrifugal pump having a constant discharge independent of downstream pressure.